diff -Naur Python-3.6.5-orig/configure.ac Python-3.6.5/configure.ac
--- Python-3.6.5-orig/configure.ac	2018-04-16 09:53:27.271360900 +0300
+++ Python-3.6.5/configure.ac	2018-04-16 09:53:27.553161400 +0300
@@ -2551,6 +2551,9 @@
 	CYGWIN*)   SHLIB_SUFFIX=.dll;;
 	*)	   SHLIB_SUFFIX=.so;;
 	esac
+	case $host_os in
+	mingw*)    SHLIB_SUFFIX=.dll;;
+	esac
 fi
 AC_MSG_RESULT($SHLIB_SUFFIX)
 
@@ -3563,6 +3566,12 @@
 	fi
 	;;
 	esac
+	case $host in
+	*-*-mingw*)
+	DYNLOADFILE="dynload_win.o"
+	extra_machdep_objs="$extra_machdep_objs PC/dl_nt.o"
+	;;
+	esac
 fi
 AC_MSG_RESULT($DYNLOADFILE)
 if test "$DYNLOADFILE" != "dynload_stub.o"
@@ -4835,6 +4844,12 @@
     *)
 	EXT_SUFFIX=${SHLIB_SUFFIX};;
 esac
+case $host_os in
+    mingw*)
+	dnl Synchronized with _PyImport_DynLoadFiletab (dynload_win.c)
+	dnl Do not use more then one dot on this platform !
+	EXT_SUFFIX=-$SOABI$SHLIB_SUFFIX;;
+esac
 
 AC_MSG_CHECKING(LDVERSION)
 LDVERSION='$(VERSION)$(ABIFLAGS)'
diff -Naur Python-3.6.5-orig/Makefile.pre.in Python-3.6.5/Makefile.pre.in
--- Python-3.6.5-orig/Makefile.pre.in	2018-04-16 09:53:24.169546100 +0300
+++ Python-3.6.5/Makefile.pre.in	2018-04-16 09:53:27.568761500 +0300
@@ -779,6 +779,12 @@
 		-DSHLIB_EXT='"$(EXT_SUFFIX)"' \
 		-o $@ $(srcdir)/Python/dynload_hpux.c
 
+Python/dynload_win.o: $(srcdir)/Python/dynload_win.c Makefile
+	$(CC) -c $(PY_CORE_CFLAGS) \
+		-DSHLIB_SUFFIX='"$(SHLIB_SUFFIX)"' \
+		-DEXT_SUFFIX='"$(EXT_SUFFIX)"' \
+		-o $@ $(srcdir)/Python/dynload_win.c
+
 Python/sysmodule.o: $(srcdir)/Python/sysmodule.c Makefile
 	$(CC) -c $(PY_CORE_CFLAGS) \
 		-DABIFLAGS='"$(ABIFLAGS)"' \
diff -Naur Python-3.6.5-orig/Python/dynload_win.c Python-3.6.5/Python/dynload_win.c
--- Python-3.6.5-orig/Python/dynload_win.c	2018-03-28 12:19:31.000000000 +0300
+++ Python-3.6.5/Python/dynload_win.c	2018-04-16 09:53:27.568761500 +0300
@@ -33,11 +33,21 @@
 #define PYD_UNTAGGED_SUFFIX PYD_DEBUG_SUFFIX ".pyd"
 
 const char *_PyImport_DynLoadFiletab[] = {
+#ifdef EXT_SUFFIX
+    EXT_SUFFIX, /* include SOABI flags where is encoded debug */
+#endif
+#ifdef SHLIB_SUFFIX
+    "-abi" PYTHON_ABI_STRING SHLIB_SUFFIX,
+#endif
     PYD_TAGGED_SUFFIX,
     PYD_UNTAGGED_SUFFIX,
     NULL
 };
 
+#if defined(__MINGW32__)
+/* avoid compile error: conflicting types for 'strcasecmp' */
+#  define strcasecmp fake_strcasecmp
+#endif
 /* Case insensitive string compare, to avoid any dependencies on particular
    C RTL implementations */